Mediterranean Diet Reduces Cardiovascular Risk

People at high risk of major cardiovascular events such as stroke and heart attack can benefit from eating a Mediterranean diet, according to a new study published in the New England Journal of Medicine.

The traditional Mediterranean diet consists of large amounts of olive oil, fruit, nuts, vegetables, and cereals along with a moderate amount of fish and poultry, and a low intake of dairy products, red meat, processed meats, and sweets. Red wine in moderation is typically consumed with meals.

Spanish researchers found that a Mediterranean diet supplemented with additional virgin olive oil or mixed tree nuts reduces the overall risk of major cardiovascular events by 30% compared to an un-supplemented low-fat diet.

Earlier studies that compared groups who followed a Mediterranean diet have consistently shown lower blood pressure or cholesterol levels compared to other diets. The Spanish study was the first to examine the diet using a large, prospective, randomized controlled trial on primary cardiovascular prevention of strokes and heart attacks in people at elevated risk.

The multicenter trial randomly assigned participants who were at high cardiovascular risk, but with no known cardiovascular disease, to one of three diets: One group followed a Mediterranean diet supplemented with extra virgin olive oil; the second followed the same diet, except supplemented with mixed tree nuts; and the third followed a reduced fat diet. All three groups could otherwise eat as much as they wanted.

The study’s enrollees included more than 7,400 people between age 55 and 80 years old for men, and 60 to 80 years old for women. Participants were followed on an average of 4.8 years. Eligible subjects had either type 2 diabetes or at least three of the following risk factors: smoking, hypertension, elevated LDL (bad) cholesterol levels, low HDL (good) cholesterol levels, overweight or obesity, or a family history of premature coronary heart disease.

Major cardiovascular events such as heart attack, stroke and death from cardiovascular disease were tracked for all three study groups. Periodic blood tests using biomarkers showed good adherence to the supplemented study diets. The olive oil and mixed nuts groups showed significant reduction in stroke incidence. A trend in reduction of heart attack and death was observed in the same groups, although neither achieved statistical significance due to their overall low incidence of those events in all groups.

Specifics of the recommended Mediterranean diet included daily: at least 4 tablespoons of olive oil, 3 servings of fresh fruit, 2 servings of vegetables per day and weekly 3 servings of tree nuts and peanuts, 3 servings of fish, 3 servings of legumes, and 7 glasses of wine.

Study participants in the Mediterranean diet groups were discouraged to eat less than 1 serving per day of spread fats, 1 serving of meat and fewer than 3 servings per week of commercial bakery goods, sweets, and pastries.

The evidence from this trial is fairly compelling. For those at risk of cardiovascular disease, a Mediterranean diet supplemented with more virgin olive oil or mixed tree nuts could reduce your risk of major cardiovascular events. The size of the protective effect is felt to be equivalent to taking statin drugs.